Improvement in slide-valves



UNITED STATES PATENT EEIGE.`

ALEXANDER K. RIDER, OF NEW YORK, N. Y., ASSIGN OR TO HIMSELF, C. H.

DELAMATER, AND G. H. REYNOLDS.

IMPROVEMENT IN SLIDE-VALVES.

Specification forming part of Letters Patent No. 116,099, dated Jane 20,1871.

To all whom it may concern:

Beit known that I, ALEXANDER K. RIDER,

of New York city, in the State of New York, i

ythis specification, and represents the novel parts, with so much oftheordinary parts asis necessary to indicate their relations thereto.Figure l is a longitudinal vertical section, and Fig. 2 is alongitudinal section on the line S S in Fig'. l. A

A is the steam-chest, and M and N are ports leading to the two ends ofthe cylinder. L isl the oriiice through which the steam is received by asuitable pipe from a boiler, not represented. C is the valve-stem, and Dis an arm on the piston-rod, which, at or near the end of eachreciprocation, strikes a tappet, O1 or G2, on the valve-stem and givesan end motion thereto. The piston is marked E and the piston-rod e. G isthe main valve. It is open through its center from top to bottom toallow the steam entering through the port or orifice L to have a freeadmission to the port M or N, according as the valve G is at one end orthe other ofits motion. There are oblique openings g g leading upwardfrom a point near the outer actingedge of the valve G, the use of whichwill be. presently explained. The valve G fits tightly to thecylinder-face Al, as is usual. It also tits tightly against the sides A2A3 of the steamchest, and it is made to fit also tightly against theupper surface or cover A4 of the steamchest by means of a bearing-ringor packingring, G', which is fitted within a suitable enlargement in thecavity through the valve G, and is pressed upward by springs K K. Itwill be understood that the steam constantly iills the space in theinterior of the valve G and of the ring GJ, While the space exterior tothe valve within the steam-chest is, the greater portion of the time, infree communication with the exhaust. Two large pieces, I and J, aremounted in the steam-chest in the positions represented. They areconnected rigidly to each other and to the valve-stem C, the connectionwith each other being maintained by the parts M' extending along eachside of the valve G in a groove or channel provided for the purpose,which they tightly iill. The piecesIandJ should not ill the entirecross-area of the steam-chest. It is better that they should not, but itis important that they fit tightly against the side A2 of the interiorof the steam-chest. The action of the external mechanism, through themedium of the valve-rod O, forces the parts I and J alternately incontact with the valve G, and by such contact pushes it directlyfor acertain portion of the early part oi' its throw. When a portion of themovement of the valve G has been thus performed a little furthermovement of the valve allows the steam to leap up through the smallinclined port or series of holes g and y iill the space behind the valveG or between it and the end of the steam-chest, which it is moving from.This causes the valve G to jump immediately to the other end of itsthrow, which movement exposes the port M fully open to receive the steamthrough the interior of the valve G from the port L, and induceimmediate commencement of the return motion of the piston E and itsconnections. The rapid motion of the valve G is arrested by thecushioning of a quantity of steam between itself and the other end ofthe steam-chest. On the completion of the return stroke of the piston Ea similar series of movements takes place in the opposite direction-thatis to say, the piece I is now brought into contact with the valve G andcompels it to commence its movement, and

at the proper stage the movement of the valve G is again completed inthe opposite direction by the rise of the steam through the port g tofill the space in the opposite end of the steam-chest.

It will be obvious that this device cannot succeed unless theexhaust-port at the end, which receives the steam through the port g, isstopped or covered temporarily. Such covering is ef' fected by theconstruction and arrangement of the side of the valve G and the edges ofthe parts I and J, which apply against the side of the steam-chest. Itis, as already remarked, important that the parts I and J shall not iitsteam-tight against all the faces in the interior of the steam-chest;but it is important that they shall iit tightly on the side whichcontains the exhaust-ports, and also that they shall fit tightly'against the adjacent surfaces ofthe valve G, over which they lap bymeans of a shoulder, as shown. The proportions are such that when theaction of the engine has, through the medium of the valve-rod C, pushedthe parts I and J, and consequently the valve G, int-o the positionwhere steam is about to leap up through the small port g and give thevalve G a further motion in that position of the parts, the exhaust-portat that end is covered by the valve G and the edge of the part I, takento gether. The uncovering of the exhaust-port is eiected almostimmediately afterward by the movement of the valve. The steam commencesto throw the valve G with so much force that its motion is continued byits momentum and by the diminishing force of the steam after it hasuncovered the exhaust-port, leaving the steam then free to rise throughthe main port N and exhaust, as above described. The motion of the valveis arrested by cushioning the exhaust at the other end of thesteam-cl1est, the valve being of such length as to cover and overrun theexhaust-port before the end of its motion.

I have represented the parts I and J as cast or otherwise formed withslight bearing-ridges or points, which hold the valve G at a littledistance oi', so as to more readily allow the steam to enter the spacebetween and act with full force on the whole area of the valve to throwit 3 but I do not esteem such aprovision essential to its full andcomplete success. The shoulder, at the side where the parts I and Jwhich, together, I sometimes term the yokelap upon the side of thevalve, is more important. I can increase the extent of this shoulder,it' desired in any case, so as to compel the exhaust to remain closeduntil the valve G has moved further. i

1. The side bearings of the main valve G and of the pieces I and J,arranged, as represented, relatively to each other and to theexhaust-ports H, so that, when the steam begins to be received upwardthrough the small port g to act on the valve G to complete its throw,the exhaust-passages or ports H shall be covered until the valve hasleaped forward, and shall then be opened widely, as herein specified.

2. The top bearing-ring G', mounted on the main valve G, and operating,as represented, against the parallel surface or bearing on the upperside of the interior of the steam-chest, opposite the cylinder-face, incombination with the means I and J, or their equivalents, for commencingthe throw of the valve G by a positive movement of the mechanism, andalso with the ports g, arranged as specified, and adapted to allow thecompletion of the throw of the valve G by direct steam-pressure, asherein specified.

In testimony whereof I have hereunto set my name in presence of twosubscribing witnesses.

Witnesses:

THOMAS D. STETsoN, A. HOERMANN.

A. K. RIDER.

